diff --git a/gen/classes.cpp b/gen/classes.cpp
index cd5f99b8..080b8b6e 100644
--- a/gen/classes.cpp
+++ b/gen/classes.cpp
@@ -39,7 +39,7 @@ static void LLVM_AddBaseClassInterfaces(ClassDeclaration* target, BaseClasses* b
             if (target->ir.irStruct->interfaceMap.find(bc->base) == target->ir.irStruct->interfaceMap.end())
             {
                 Logger::println("adding interface '%s'", bc->base->toPrettyChars());
-                IrInterface* iri = new IrInterface(bc, NULL);
+                IrInterface* iri = new IrInterface(bc);
 
                 // add to map
                 target->ir.irStruct->interfaceMap.insert(std::make_pair(bc->base, iri));
@@ -242,16 +242,14 @@ void DtoResolveClass(ClassDeclaration* cd)
 
         // set vtbl type
         TypeClass* itc = (TypeClass*)id->type;
-        const LLType* ivtblTy = getPtrToType(itc->ir.vtblType->get());
-        fieldtypes.push_back(ivtblTy);
+        const LLType* ivtblTy = itc->ir.vtblType->get();
+        assert(ivtblTy);
+        Logger::cout() << "interface vtbl type: " << *ivtblTy << '\n';
+        fieldtypes.push_back(getPtrToType(ivtblTy));
 
         // fix the interface vtable type
-    #if OPAQUE_VTBLS
-        iri->vtblTy = isaArray(itc->ir.vtblType->get());
-    #else
-        iri->vtblTy = isaStruct(itc->ir.vtblType->get());
-    #endif
-        assert(iri->vtblTy);
+        assert(iri->vtblTy == NULL);
+        iri->vtblTy = new llvm::PATypeHolder(ivtblTy);
 
         // set index
         iri->index = interIdx++;
@@ -421,7 +419,7 @@ void DtoDeclareClass(ClassDeclaration* cd)
             nam.append("6__vtblZ");
 
             assert(iri->vtblTy);
-            iri->vtbl = new llvm::GlobalVariable(iri->vtblTy, true, _linkage, 0, nam, gIR->module);
+            iri->vtbl = new llvm::GlobalVariable(iri->vtblTy->get(), true, _linkage, 0, nam, gIR->module);
             LLConstant* idxs[2] = {DtoConstUint(0), DtoConstUint(idx)};
             iri->info = llvm::ConstantExpr::getGetElementPtr(irstruct->interfaceInfos, idxs, 2);
             idx++;
diff --git a/ir/irstruct.cpp b/ir/irstruct.cpp
index de8c16b5..3d000090 100644
--- a/ir/irstruct.cpp
+++ b/ir/irstruct.cpp
@@ -4,15 +4,11 @@
 #include "ir/irstruct.h"
 #include "gen/irstate.h"
 
-#if OPAQUE_VTBLS
-IrInterface::IrInterface(BaseClass* b, const llvm::ArrayType* vt)
-#else
-IrInterface::IrInterface(BaseClass* b, const llvm::StructType* vt)
-#endif
+IrInterface::IrInterface(BaseClass* b)
 {
     base = b;
     decl = b->base;
-    vtblTy = vt;
+    vtblTy = NULL;
     vtblInit = NULL;
     vtbl = NULL;
     infoTy = NULL;
@@ -24,6 +20,7 @@ IrInterface::IrInterface(BaseClass* b, const llvm::StructType* vt)
 
 IrInterface::~IrInterface()
 {
+    delete vtblTy;
 }
 
 //////////////////////////////////////////////////////////////////////////////
diff --git a/ir/irstruct.h b/ir/irstruct.h
index addbabe4..a3e40d8a 100644
--- a/ir/irstruct.h
+++ b/ir/irstruct.h
@@ -11,13 +11,8 @@ struct IrInterface : IrBase
     BaseClass* base;
     ClassDeclaration* decl;
 
-#if OPAQUE_VTBLS
-    const LLArrayType* vtblTy;
-    LLConstantArray* vtblInit;
-#else
-    const LLStructType* vtblTy;
-    LLConstantStruct* vtblInit;
-#endif
+    llvm::PATypeHolder* vtblTy;
+    LLConstant* vtblInit;
     LLGlobalVariable* vtbl;
 
     const LLStructType* infoTy;
@@ -26,11 +21,7 @@ struct IrInterface : IrBase
 
     int index;
 
-#if OPAQUE_VTBLS
-    IrInterface(BaseClass* b, const LLArrayType* vt);
-#else
-    IrInterface(BaseClass* b, const LLStructType* vt);
-#endif
+    IrInterface(BaseClass* b);
     ~IrInterface();
 };